Non-woven fabrics are very common in a variety of uses, ranging from cosmetic tissues to industrial applications. For cleaning purposes, non-woven fabrics are used in all applications, from gentle cosmetic wipes to robust industrial cleaning materials. Such Non-woven fabrics can be manufactured in different ways, and one of the industrially efficient processes employed for this purpose is known in the art as “Spunlace”. Spunlace, or Hydro-entanglement, is a technology that uses water jets to cause the entanglement of fibers and thus the formation of the fabric. In this it is unique among the non-woven technologies. The main consequence of the hydro-entanglement technique is the fact that the fabric at the end of its creation step is wet and will require a drying step.
To enhance the cleaning operation to be performed, be it gentle cosmetic cleaning or strong industrial cleaning, it is desirable to add solid physical elements to the surface of the fabric, which will enhance the desired cleaning operation. These solid elements may be of an abrasive nature, with varying degrees of abrasiveness: for the purpose of household cleaning, with low level of abrasiveness, and for industrial cleaning purposes, with higher level of abrasiveness, whereby in both cases, the abrasive nature of the fabric is derived both from the solid elements as well as from the fact that they are raised above the surface. These solid elements may consist, in one instance, of soft, raised shapes, which through their raised position and solid consistency are suitable as a soft abrasive material for cosmetic purposes, i.e., exfoliation. The soft raised elements, when larger in size than desired for soft abrasive purposes, may also have application as non-slip surfaces. In addition, the technique may be employed for the formation of esthetically appealing patterns onto fabric, for decorative purposes.
It is known in the art to provide abrasive elements by creating them on the finished, dry non-woven fabric. As will known to person skilled in the art, there is also no limitation regarding the shape of the abrasive elements, which may be simple dots or may consist of more complex shapes. The degree of abrasiveness depends on the type of material of which the elements are made (e.g., hard or soft polymer), as well as from the density of such elements on the surface (i.e., the fraction of the fabric's surface that is covered by them), their shape and their height.
U.S. Pat. No. 5,213,588 relates to an abrasive wiping article and process for its preparation, which involves printing a pattern on a non-woven substrate to create an abrasive product.
DE 19851878 teaches the preparation of a cleaning article consisting of a non-woven substrate with polymeric particles distributed thereon.
Other ways to create products of this type involve the application of abrasive elements to a finished fabric. However, creating such abrasive surfaces is expensive because of the need to post-process the non-woven fabric at the end of its manufacturing line. Furthermore, due to the nature of the applied solid elements, the amount of material that is required to be deposited in order to obtain the required physical effects is substantial, making the process not economically viable. This fact has so far severely limited the usefulness of such fabrics.
It would therefore be highly desirable to provide a process for manufacturing non-woven fabrics provided with sparse elements of physical consistency on their surface, without the need for expensive and time-consuming post-processing operations.
It is an object of the present invention to provide an in-line process for the manufacturing of such improved fabrics, with control over both the abrasiveness and the pattern height and overcomes the drawbacks of the priori art.
It is a further object of the invention to provide a process, whereby only small amounts of the abrasive material are deposited, while retaining control over the level of abrasive properties, be it strong abrasive for cleaning purposes or soft abrasive for cosmetic exfoliating.
It is yet another object of the invention to provide a process which imparts chemical stability to the solid elements after deposition.
It is still another object of the invention to provide an in-line process that does not require off-line processes or additional elements in the process, while retaining speed and ease of manufacturing operation.
It is still a further object of the invention to provide finished fabrics of high-quality, improved by the addition of elements of physical consistency on their surface.
It is yet another object of the invention to provide materials suitable to be applied to non-woven fabrics in an in-line process to create solid elements on its surface.
Other objects and advantages of the invention will become apparent as the description proceeds.